Electrical switch



Feb. 17, 1953 l. G. 0. BROWN 2,629,037

ELECTRICAL SWITCH Filed Sept. 8, 1956 2 SHEETS-SHEET 1 I nvenlor fl giqf I By [M Attorney:

Feb. 17, 1953 l. G. 0. BROWN 2,629,037

I ELECTRICAL SWITCH Filed Sept. 8, 1950 2 SHEETS-SHEET 2 Attorneys Patented Feb. 17, 1953 ELECTRICAL SWITCH Ivan G. 0. Brown, Yate, England, assignor to The British Vacuum Cleaner and Engineering Company Limited, Leatherhead, England, a British comp any Application September 8, 1950, Serial No. 183,876 In Great Britain May 4, 1949 3 Claims.

This invention relates to electrical switches and the object of the invention is to provide a new and improved switch mechanism capable of operating accurately and consistently, and which will provide a positive snap action in both the contact-making and contact-breaking operations. A further object is to provide a switch which will be automatically re-set in the open condition after closure thereof.

Whilst the switch according to the invention is capable of application to a time recording device of the kind referred to in co-pending application Ser. No. 177,301, filed August 2, 1950, and will hereinafter be described as employed in such a device, the invention is not limited in its application to such devices but may equally well be employed in the operation of many other kinds of mechanisms in which the use of a switch of the above described characteristics is desirable or necessary.

According to the invention a switch mechanism is provided wherein a fixed contact carrying member has pivotally mounted thereon a movable contact carrying member urged by resilient means to engage the movable contact with the fixed contact but normally restrained against such movement by engagement with a pivotal sear the tripping of said sear by an independent actuating member effecting engagement of the movable contact with the fixed contact under the action of said spring and completing an electrical circuit effecting movement of an operating member to disengage said movable contact and re-engage said sear therewith.

Reference will now be made to the accompanying drawings which illustrate a preferred form of construction of the switch mechanism according to the invention mounted in a time recording apparatus of the kind described in the aforesaid co-pending application, and in which Figure 1 is a side elevation of the switch mechanism in its normal, inoperative position,

Figure 2 is a view similar to Figure 1 showing the switch in its closed, operative position, and

Figure 3 is a view similar to Figure 2 showing the condition of the switch mechanism immediately prior to its return to the position shown in Figure 1.

Like parts of the apparatus shown in the accompanying drawings and described herein and shown and described in the specification and drawings of the aforesaid prior patent application will bear like reference numerals.

The switch mechanism is mounted in a side plate I of the aforesaid time recorder and is mounted on a substantially triangular plate secured to the side plate by bolts 9i, the plate 90 being formed with a flange 92 extending inwardly therefrom. An insulating plate 93 is secured on said flange 92 and a terminal 94 and a contact holder 95 are mounted on said plate 93 so as to be insulated therefrom and each other. The contact holder 95 has mounted therein a carbon contact 96.

Pivotally mounted on a spindle 91 secured in the lower portion of the plate 90 is a movable contact carrying member 98 formed as a substantially inverted T-shaped plate the upper arm 99 of which is formed with a fiange I00 on which is mounted an insulating plate 93A in which is mounted a contact holder 95A carrying a carbon contact 96A. A tension spring IIlI secured at one end to the upper portion of the arm 99 and at its other end to the flange 92, urges the contact holder 95A and the contact 96A carried therein, into engagement with the fixed contact 96 and contact holder 95. The lower part of the movable contact carrying member 98 comprises two oppositely extending arms I02, I03, the former of which has a flange I04 bent inwardly from the lower edge thereof whilst the latter has a flange I05 bent outwardly, that is towards the side plate I, from the upper edge thereof.

Also pivotally mounted on a spindle I06 secured to the plate 90 is a sear lever I01 extending downwardly therefrom and formed at its end with a sear I08 adapted to engage under the flange I04 on the pivotal contact carrying member 98, said lever I01 being urged in a direction to effect engagement of said scar and said flange by means of a tension spring I09 secured at one end to said sear lever I01 and at the other end to a flange IIO bent inwardly from the central portion of the arm 99.

The arm N33 has mounted therein a pin III extending therefrom towards the side plate I.

The contact holder 95A is connected with the terminal 94 by means of a flexible wire II2.

Pivotally mounted in the side plate I is a shaft 3 on which is secured a short link I M the free end of which carries a spindle II5 on which is pivotally mounted intermediate its ends an actuating lever IIG. One end of the lever H6 is formed with a flange III extending laterally therefrom and adapted to bear against the under side of the fiange I04. The other end of the lever II6 has secured thereto one end of a tension spring II8 secured at its other end to a pin II9 thereby pivoted in a direction to engage the flange II'I with flange I04.

Also secured on the shaft I I3 is a ladder lever I20 a portion only of which is shown in Figure 1 the said ladder lever being formed with a number of steps I2 Ion which a card inserted into the time recorder for stamping is adapted to bear.

Mounted in the upper part of the side plate I is a shaft I22 on which is mounted a short link I23 pivotally mounted at its free end on a pin I24 extending laterally from the upper end of an operating lever I25 formed with a slot I26 in which freely engages a guide pin I 21 secured to the side plate I. The lower end of the lever I25 is pivotally mounted to a link I28 secured on the armature I29 of an electro-magnet I30 secured to the said side plate I. The armature I29 is pivotally mounted on a shaft I3I. The said lever I25 is urged in an upward direction by means of-a spring I32 secured at one end to a pin I33 extending laterally from the -:lever I25 and atits other end to a pin I34 mounted in the side plate .I. The lever 4254s also formed with a further pin I35 extending laterally therefrom and adapted to abut the upper surface of the flange I95 of the-pivotal contact carrying member 98.

The operation oi the switch mechanism is as follows:

It will be assumed that the parts are in the position shown in Figure 1. On the insertion of award into the machine for stamping, the lower -edge of the card bears on one of thesteps i2l of the ladder lever I20, the latter being adjustable by a suitable means (not shown) so as to present:a different step for abutment by a card, in accordance with-the passage of fixed interval of time. Downward movement of the card on engagementwith a step I2I causes pivotal movement of said ladder lever I20 to impart rotation to the shaft I I3, the link I M secured thereon being likewise pivoted through a corresponding angular movement.

As a result of the aforesaid angular movement imparted to link I'M the lever H5 pivotally mounted on said'link' is moved to the left, as viewed in Figure l and the flange IIl formed at the end of said'li'nk trips the sear I08 out of engagement with flange I94 on the arm I02 of the pivotal contact carrying member.

i On release by the sear I the pivotal con-tact carrying member rotates anti-clockwise about its pivot 91 bringing the contact 96A into engagement with contact 95 of the fixed contact carrying member. The making of -this 'contactcompletes an electrical circuit' (not shown) which "energises the electro-magnet' I30, the armature I29 being thereby rotated about its pivot I3I and tcarrying with it thelink I28. The pivotal move- "ment of the link I28 "cause-s"downward movement of the operating lever I25 pivotally attached thereto,'"bringing the pin -I35on said "lever into abutment withthe upperface-of flange Iduring' such downwardmovement and thereby causing the pivotal contact carrying member to rotate clockwise and disengage contact 96A from contact-96 (see Figure 3). During the clockwise rotationof the pivotal contact carrying member 98 the'pin III-' on the arm I03 thereof abuts the lever H 6 anddepresses the latter, bringing the flange Illoutof engagement with flange I94 on the arm I02 of said contact carrying member and thuspermitting the sear I0 8 on lever I01 to move 1 to a position ready for re-engagement with the said-flange I04 to restrain the pivotal contact oarrying member 98 againstmovementin a di-;

rection to close the contacts of the switch, that is, against anti-clockwise rotation.

When the card inserted into the machine is removed therefrom the ladder lever I20 returns to its normal position, under the action of spring II 8, rota-ting clockwise and thereby bringing the lever II 6 from a position in which the flange II'I lies under the sear I08 (Figure 3) to a position in which it abuts the under surface of flange I04, the par-ts now being in the position shown in Figure l and ready for a further operation.

I claim:

1. A switchmechanism comprising a fixed contact carrying member, a pivot thereon, a movable contact carrying member pivotally mounted on said pivot and consisting of an upper arm car- 'rying a contact and a pair of lower arms projecting respectively from opposite sides of the pivotal axis of the movable contact carrying member, resilient mean-s urging .the movable contact carrying member to engage the contact thereon with the fixed contact, a-pivoted sear having means urging it toward engagement with the lower arm at one side of the pivotal axis of the movablecontact member to normally restrain the latter member from engaging .the movable contact with the fixed contact, an actuating member positioned to act on the sear to trip'i-t and thereby cause engagement of the'movable contact with the fixed contactv under the influence of said resilient means, and an operating member engageable withthe lower arm of the movable contact carrying member at the opposite side of its pivotal axisand operative to rock the movable contact carryingmemberinto position to disengage the movable contact from the fixed contact and for re-engagemen-t of the sear with the movable contact carrying member-to hold-the movable contact in open circuit position.

wherein the lower arm of said m ovable contact carrying member whichis en-gageableby said operating member is formed with an abutment adapted, on movement of said operating'member to open said contacts, to pivot said actuating member clear of said lower arm on said movable contact carrying member to permit re-engagement of said sear therewith.

IVAN 'G; 0. BROWN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 508,652 Thomson Nov; 14, 1893 640,062 Winfield Dec. 26,- 1899 893,902 Cleary July 21, 1908 1,319,880 Little Oct. 28, 1919 1,512,064 Sundh-aussen Oct. 21, 1924 1,950,022 Davis Mar. 6, 1934 2,230,680 Ford Feb. 4, 1941 

